The purpose of the study is to determine whether women who are sterilized are at increased risk of (1) overall mortality, (2) hospitalization, (3) hysterectomy and other gynecologic surgery, (4) cardiovascular disease, and (5) breast, endometrial, and ovarian cancer. Additional outcomes to be investigated, include: (1) hospitalization for menstrual disturbances, (2) endometriosis, (3) pelvic inflammatory disease (PID), and (4) ectopic pregnancy. The methods of sterilization to be studied include the Pomeroy technique, unipolar and biopolar fulgeration, and the Fallope ring. Where possible, method-of occlusion specific analyses will be conducted. The sterilized women will be categorized by interval or post-partum sterilization. The selection criteria for the matched comparisons will be the same for women with post-partum and interval sterilization (see A.2 below). Analysis will be performed in both a matched and unmatched fashion. In addition, several smaller studies will be conducted including two validity studies and a substudy of women participating in a Multiphasic Health Checkup (MHC) matched to both wives of vasectomized men and women delivering live-borns during the same period. The contractor will consider methods to adjust for major confounding factors identified in this substudy or identified by a sister project being performed at the Puget Sound Group Health Cooperative (GHC).